David Cameron was under fresh pressure to hold a referendum on Europe last night – as France and Germany called for the controversial Lisbon Treaty to be redrawn.

In a surprise move, German chancellor Angela Merkel and French president Nicolas Sarkozy called for a new EU treaty to be agreed within two years.

In a joint statement the two leaders said it was ‘necessary to revise the (Lisbon) Treaty’ in order to deal with the fallout from the financial crisis.

Ministers have pledged to introduce a ‘referendum lock’ which would require the Government to hold a public vote on any treaty changes affecting Britain.

But privately they are desperate to avoid a referendum on a subject which could split the coalition partners. Douglas Carswell, a senior Eurosceptic Tory, last night warned that right-wingers would use any move to renegotiate the Lisbon Treaty to press for a referendum.